The present invention relates to a device for manufacturing cushions filled with a gaseous medium, for instance air, from synthetic foil, for instance tubular foil.
International patent application WO94/07678 describes such a device for manufacturing small air-filled cushions or bags, for use as protective filling material when packaging fragile parts and other objects in cargo boxes or the like. The cushions are made by forming a seal over the tubular foil, introducing air into the foil by inserting a needle through the wall of the tubular foil, and subsequently forming another seal over the tubular foil where the air was introduced to close off the cushion and to seal off the hole made by the needle. Consecutive cushions leave the device separately or as a number of cushions connected to each other, which can be separated in order to be used separately.
In practice it appeared that said device has some limitations and drawbacks, and that many cushions are not sufficiently filled with air. Because of the flexible tubular foil it is difficult to insert the needle through the wall of the tubular foil, without the needle pricking through the wall (or the opposite wall) for a second time. When this happens air escapes via the second hole before the holes have been sealed off. When the second hole is outside the area that will be sealed off the air will continuously escape even after the cushion has been sealed off. Moreover said known device for manufacturing bags filled with a gaseous medium is provided with various stations for performing the various necessary treatments, such as sealing, the introduction of air, the separation of adjacent bags. This renders the device somewhat sizeable.
It is amongst others an object of the present invention to provide a device for manufacturing a cushion filled with a gaseous medium, with which cushions can reproducibly be filled, and which has a very compact construction.
To that end the present invention in a first aspect provides a device for manufacturing cushions filled with a gaseous medium from synthetic tubular foil, which device is provided with supply means for supplying flexible tubular foil in a supply direction, perforation means for making a row of perforations in the tubular foil, which row extends transverse to the supply direction, which perforation means are situated at a first station, introduction means for introducing a gaseous medium, which introduction means are situated at the first station, sealing means for making a transverse seal on either side of the row of perforations for closing off the tubular foil and sealing off the row of perforations, which sealing means are situated at the first station, in which the supply means for supplying flexible tubular foil in a supply direction are provided with a plate which can be placed within the tubular foil and is kept within the tubular foil while the device is operative, which plate has a top side and a bottom side situated at a distance from it, a first side wall and a second side wall situated at a distance from it for keeping the walls of the tubular foil apart, in which at least one of the side walls of the plate is provided with a continuous opening for guiding the gaseous medium to the tubular foil, the top side and bottom side of the plate being provided with at least one retaining recess, the retaining recesses being situated opposite each other, and with at least two retaining rollers for abutment in the respective retaining recesses, in which the introduction means for introducing a gaseous medium are provided with at least one blast pipe mounted on a vise-grip wrench, which vise-grip wrench can be moved to and from a respective side wall of the plate until in abutment with the tubular foil, the blast pipe being moveable until in the continuous opening for making an introduction perforation for introducing a gaseous medium in the tubular foil. By inserting gaseous medium in the tubular foil in this manner, and sealing off the perforation on either side after that, a reproducible filling with gaseous medium is guaranteed. Because all treatments take place at one station, not only is the construction of the device compact, but it is also possible to freely choose the length of the cushion filled with gaseous medium. In the known device the length of the cushion is determined by the distance between the separate stations, and therefore cannot vary. Moreover perforation of the tubular foil takes place in a very defined manner by the blast pipe, also because the tubular foil is clamped between the plate and vise-grip wrench during perforation. As a result a reproducible filling of the cushion is realized.
According to a second aspect of the invention a device is provided for manufacturing cushions filled with a gaseous medium from synthetic tubular foil, which device is provided with supply means for supplying flexible tubular foil in a supply direction, perforation means for making a row of perforations in the tubular foil, which row extends transverse to the supply direction, which perforation means are situated at a first station, introduction means for introducing a gaseous medium, which introduction means are situated at the first station, sealing means for making a transverse seal on either side of the row of perforations for closing off the tubular foil and sealing off the row of perforations, which sealing means are situated at the first station, in which the supply means for supplying flexible tubular foil in a supply direction are provided with a plate which can be placed within the tubular foil and is kept within the tubular foil while the device is operative, which plate has a top side and a bottom side situated at a distance from it and a front wall for keeping the walls of the tubular foil apart, in which the plate is provided with an opening continuous from the top side to the bottom side and with at least one duct going from the opening to the front wall for guiding the gaseous medium to the tubular foil, the top side and bottom side of the plate being provided with at least one retaining recess, the retaining recesses being situated opposite each other, and with at least two retaining rollers for abutment in the respective retaining recesses, in which the introduction means for introducing a gaseous medium are provided with at least one blast pipe mounted on a vise-grip wrench, which vise-grip wrench can be moved to and from the top side or bottom side of the plate respectively until in abutment with the tubular foil, the blast pipe being moveable until in the opening for making an introduction perforation for introducing a gaseous medium in the tubular foil. Here perforation of the tubular foil by the blast pipe takes place from above in a very defined manner. The thickness of the plate makes it possible that the blast pipe extends into the opening and therefore does not extend through the other side of the tubular foil.
According to a third aspect the present invention provides a device for manufacturing cushions filled with a gaseous medium from synthetic tubular foil, which device is provided with:
supply means for supplying flexible tubular foil in a supply direction,
perforation means for making a row of perforations in the tubular foil, which row extends transverse to the supply direction, which perforation means are situated at a first station,
cutting means for making a longitudinal cut in the tubular foil,
introduction means for introducing a gaseous medium, which introduction means are situated at the first station,
sealing means for making a transverse seal on either side of the row of perforations for closing off the tubular foil and sealing off the row of perforations, which sealing means are situated at the first station,
in which the supply means for supplying flexible tubular foil in a supply direction are provided with a plate which can be placed within the tubular foil and is kept within the tubular foil while the device is operative, which plate has a top side and a bottom side situated at a distance from it, a first side wall and a second side wall situated at a distance from it for keeping the walls of the tubular foil apart,
in which at least one of the side walls of the plate is provided with a continuous opening for guiding the gaseous medium to the tubular foil, the top side and bottom side of the plate being provided with at least one retaining recess, the retaining recesses being situated opposite each other,
sealing means for arranging a longitudinal seal for closing off the longitudinal cut of the tubular foil,
and with at least two retaining rollers for abutment in the respective retaining recesses,
in which the introduction means for introducing a gaseous medium are provided with at least one blast pipe mounted on a vise-grip wrench, which vise-grip wrench can be moved to and from a respective side wall of the plate until in abutment with the tubular foil, the blast pipe being moveable until in the continuous opening and in the longitudinal cut of the tubular foil for introducing a gaseous medium in the tubular foil.
According to a fourth aspect the present invention provides a device for manufacturing cushions filled with a gaseous medium from synthetic centrefold foil, which device is provided with:
supply means for supplying flexible foil in a supply direction,
perforation means for making a row of perforations in the foil, which row extends transverse to the supply direction, which perforation means are situated at a first station,
introduction means for introducing a gaseous medium, which introduction means are situated at the first station,
sealing means for making a transverse seal on either side of the row of perforations for closing off the foil and sealing off the row of perforations, which sealing means are situated at the first station,
in which the supply means for supplying flexible foil in a supply direction are provided with a plate which can be placed within the foil and is kept within the foil while the device is operative, which plate has a top side and a bottom side situated at a distance from it, a first side wall and a second side wall situated at a distance from it for keeping the walls of the foil apart,
in which at least one of the side walls of the plate is provided with a continuous opening for guiding the gaseous medium to the foil, the top side and bottom side of the plate being provided with at least one retaining recess, the retaining recesses being situated opposite each other,
sealing means for arranging a longitudinal seal for closing off the centrefold foil,
and with at least two retaining rollers for abutment in the respective retaining recesses,
in which the introduction means for introducing a gaseous medium are provided with at least one blast pipe mounted on a vise-grip wrench, which vise-grip wrench can be moved to and from a respective side wall of the plate until in abutment with the foil, the blast pipe being moveable until in the continuous opening and in the centrefold foil for introducing a gaseous medium in the tubular foil.